Make no mistake: The Pentagon's got plenty of secrets you probably don't even want to know about. But there are at least a handful they likely wish had stayed a bit more covert.

Some of 'em have been talked about for years -- and new intel is still creeping out. Old documents from the CIA's MK-ULTRA program, which plied unwitting participants with mind-altering drugs, have been released as recently as last year. And the Pentagon Papers, officially declassified just this past summer, reveal disturbing details about U.S. activities during in the Vietnam War.

Try as they might, it seems top brass just can't keep every classified program entirely under wraps. And in this Internet era, it's arguable that we know more than ever about their covert activities. A combination of insider leaks, sly reporting and grainy photographs -- all distributed online -- have shed plenty of light on some of the military's biggest secrets. From stealth helicopters to undisclosed prisons, check out nine recent Pentagon programs you never should have been privy to.

The Navy's Souped-Up Sub

It's the most covert submarine in the American arsenal. Since the sub's 2004 launch, experts have speculated that USS Jimmy Carter was designed with classified spy missions in mind. Allegedly, the sub is able to slip into enemy ports undetected and even tap into the underwater fiber-optics of foes to listen in on undersea chatter. USS Jimmy Carter may have done just that last year, when it was quietly deployed to spy on North Korea -- one of the only known missions the sub has ever taken.

What else can USS Jimmy Carter, one of the Navy's three Seawolf-class Submarines, accomplish? Nobody's quite sure, because Navy officials haven't commented on exactly what kinds of tech the seafarer is equipped with. But the Jimmy Carter does boast unprecedented hull space, to store unmanned aerial and undersea vehicles for whatever deadly missions our former president's namesake needs to embark on.

Photo: Department of Defense

The Air Force's Secret Space Plane

The Air Force's experimental X-37B space plane has been orbiting the planet since last April. What exactly the 29-foot, fully robotic X-37B is doing up there? Much to the irritation of other nations, no one has any idea.

Officials have said the spacecraft is designed to conduct orbital science experiments, but experts outside the Air Force speculate that X-37B is capable of doing much more than that. The craft might be hauling supplies to the International Space Station, tampering with enemy satellites or even doing some sky-high super sleuthing on our Earthly foes. Whatever the X-37B is up to, no one's quite sure when the aircraft's mission will come to an end: Air Force officials in November extended the X-37B's mysterious orbit indefinitely.

Video: U.S. Air Force Space Command

America's Osama-Killing Helicopter

From specially-trained SEALS to heaps of classified surveillance, the raid that killed Osama Bin Laden couldn't have been stealthier. Months later, plenty of of the secretive details have been pieced together. One mystery that remains? The identity of the far-out helicopter American operatives were flying.

When photos emerged of a chopper that had crashed during the raid, experts were miffed: A shield to silence the helo's rotor, along with special windshield coating to deflect detection radar, indicated that this 'copter was unlike anything in the military's arsenal. Most importantly, the apparent primacy of undetectable airflight suggested that the American government was wary of interference as operatives flew through the airspace of our alleged anti-Osama ally, Pakistan.

Photo: Reuters

America's Secret Afghan Prisons

Pentagon officials swore they weren't operating a single covert detention center in Afghanistan. They stressed that Obama's 2009 executive order to ban “Black Site” detention centers was being upheld. And of course, officials told reporters and human rights organizations, there was absolutely no detainee abuse going on at any Afghan site.

That may not have been the case. In a blockbuster story published earlier this year, Associated Press reporter Kimberly Dozier revealed 20 secret Afghan detention centers, all run by the elite Joint Special Operations Command. Detainees were allegedly punched, kept in cold, constantly lit solitary confinement and stripped nude, among other abuses. Sadly, rumors of hushed-up, violent detention centers add to the lengthy list of alleged torture committed by U.S. personnel in Iraq, Afghanistan and Guantanamo Bay.

Photo: U.S. Air Force

Our Secret Pakistan Army

Among Pakistani politicians and intelligence agents, friends of the U.S. are becoming increasingly hard to find. The final hope for American officials? A secret office inside the Pakistani intelligence apparatus, being paid off by American officials to ensure cooperation.

The T Wing office, a group of operatives and analysts working for Pakistan's Inter-Services Intelligence (ISI), were unearthed just last week by Newsweek's Eli Lake. And the office isn't just doing lip service in exchange for American cash: Lake reports on one recent T Wing-led surveillance effort that led to the detainment and interrogation of a senior al-Qaida operative.

Of course, this covert cooperation might not last. With U.S-Pakistani relations more fragile than ever, there's no question that T Wing's viability is at risk.

Photo: Pakistan's Inter Services Public Relations

Darpa's Afghan Spy Machine

The contest seemed innocuous enough: In 2009, the Pentagon's far-out research arm, Darpa, offered $40,000 to the first civilian team able to find nine red balloons placed around the country. Little did the winning team of MIT grad students know, their crowdsourced strategy would inspire a top-secret surveillance program that was rushed into Afghanistan mere months later.

Called "Nexus 7," the intelligence program apparently analyzes vast swaths of data and then helps personnel draw conclusions about relative instability in Afghan communities. But as Danger Room head honcho Noah Shachtman pointed out earlier this year, the program's mostly busy analyzing fruit prices. Maybe that's why the Pentagon tucked Nexus 7, estimated to have cost $30 million last year, deep into their budget. In the words of some frontline intel aces, Nexus 7 is basically "a glorified grad school project."

Photo: U.S. Air Force

Top-Secret Bomb Tech

In Iraq, they were the invaluable tool that gave American soldiers a much-needed advantage over remote-controlled bombs. But the Pentagon has remained incredibly mum on the gadgets, called radio-frequency jammers. Reporters who mentioned them overseas were booted back stateside.

That covert attitude toward jammers, of which the military has bought an estimated 50,000 at a cost of $17 billion, allowed soldiers to quietly fight back against the insurgents' tactic of choice -- remote-controlled bombs -- in the first several years of this decade's wars. Of course, our enemies adapted, and deployed new bombs to foil new tech. Now, the Pentagon is ever so quietly funding the ultimate bomb jammer: One that, as Noah learned earlier this year, could also find bombs, interrupt GPS signals, eavesdrop and even screw with enemy drones.

Photo: ITT

The CIA's Secret Somali Plot

Since 9/11, CIA agents have been quietly lurking in Somalia, conducting a shadow war that aims to find, capture or kill al-Qaida operatives hiding out in the lawless country.

For years, little was known about the covert operations. But in recent months, largely thanks to ace reporting from Army Times' Sean Naylor, more intel has emerged. For one thing, CIA agents spent years bluffing to local warlords about the presence of surveillance drones – which were actually tied up over Iraq – monitoring Somalia's airspace. The lie worked: Warlords offered up information that led to several dangerous weapons being nabbed, and the elimination of several high-profile terror leaders, including Aden Hashi Ayro, killed by a Navy cruise missile strike in 2008.

And, as Jeremy Scahill at The Nation revealed, the CIA's also been operating a hush-hush detention center -- exactly the kind of "black site" the U.S. government said it'd get rid of.

Of course, that “shadow war” has become a little more obvious. U.S officials don't really wanna talk about it, but American drones are now flying over – and attacking – the country.

Photo: Department of Defense

The Beast of Kandahar

It was mysterious enough when rumors started circulating that the U.S. military had a top-secret spy drone. And last week's announcement from Iran that they had downed one of those covert flyers, an RQ-170 – dubbed “The Beast of Kandahar” – adds even more intrigue to the lore of this covert American aircraft.

Grainy photos of the batwing-shaped drone first appeared two years ago. Analysis of the photos suggested the drone's sleek shape was designed to elude radar detection. Speculation on the drone's use has persisted, with experts guessing it was spying on Iran's nuke program or even testing new microwave weaponry. One thing, at least, we know for sure: The drone was deployed to evade Pakistani detection as CIA operatives collected intel on Bin Laden's compound. Whether Iran actually did capture a Beast remains unknown, but at least in this latest chapter of the RQ-170 mystery, relevant photos are a little higher quality.